Work will continue on the amino acid sequences of myoglobins from 9 diving mammals. Minor components will be defined wherever practical. A procedure for stepwise degradation from the carboxyl terminus is under development. The mapping of reactivity in solution for comparison with crystalline structures is continuing. Oxygen and proton equilibria of myoglobins are being systematized. NMR studies with H1 and C13 are being extended. The carbamino behavior of hemoglobin and of vasoactive peptides is under study. The methodology is being extended to hemoglobin S.